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Amorphous silicon bolometers with different pixel patterns are investigated for far infrared detection. Devices with floating resonator structure are measured for resistances and temperature coefficient of resistance (TCR) values. The results show normal leg geometry has high TCR (∼ −4%/°C) and moderate resistance. Thus the pixel pattern is suitable for infrared detecting applications.
The electromigration test of the microbump interconnects with Cu/Cu6Sn5/Cu structure is reported in this study. This Cu6Sn5 intermetallic compound layer was single-crystal like. The diameter of the microbumps in die-to-die stacking was 30 µm. Test vehicles were applied by a current density of 2.2×105 A/cm2 and settled on a hotplate at 150°C. The resistances of the microbumps were simultaneously monitored...
This paper discusses about limiting factors of RF-to-DC rectifying efficiency in cellular and Wi-Fi band from 700 MHz to 5800 MHz for different frequency range, input power ranges, and load resistance based on our analytical study findings. We also presents two novel rectifying circuitry modifications for improving rectifying efficiency All the results are obtained from ADS circuit simulations with...
Theoretical calculation and simulation of FEM were proposed to explain the decline of change in resistance in Cu-Sn microbumps during the electromigration test. The IMC transformation from Cu6Sn5 to Cu3Sn was supposed to be the reason. Being aware that the dimension keeps shrinking, the behavior for various solder diameters was also investigated.
In this study, we use the Cu/SnAg/Ni/Cu joint with a thickness of 7μm/8μm/2μm /5μm and 7μm/16μm/2μm /5μm. The diameter of the solder joint is about 30 μm and the UBM opening is 18 μm in diameter with 60 μm pitches. In order to measure the resistance changes, it was fabricated which constitute four probes. By using this method we can measure the resistance changes in microbump excluding the resistance...
Three dimensional integration circuits technology has received much attention recently since the demands of functionality and performance in microelectronic packaging for electronic products are rapidly increasing. For high-performance 3D chip stacking, high density interconnections are essential. In the current types of interconnects, solder micro bumps have been widely used and thermocompression...
Recently, three dimensional integration circuits technology has received much attention since the demands of functionality and performance in microelectronic packaging for electronic products are rapidly increasing. For high-performance 3D chip stacking, high density interconnections are required. In the current types of interconnects, solder micro bumps have been widely adopted. For fine pitch solder...
An immortal solder micro-bump (μbump) electromigration (EM) lifetime has been demonstrated for 3D IC integration. This ultimate goal was achieved under strictly controlled conditions, including the optimal design of bump metallurgy, geometry, optimized processes, along with well-defined stressing conditions and manufacturing window. The current carrying capability and EM lifetime of μbump have been...
This paper briefly reviews several circuits of white light LED driving structure, which includes the voltage regulator and current limiting resistance model, current regulator and current limiting resistance model, multiple current regulator model and inductance boost model. The paper also presents power loss analysis model to realize circuits performance. The analysis models can be used in the pre-driver...
On one hand, with the rapid increase of integrated circuits (ICs) I/O number, the traditional package technique does not meet the need of pioneer development. On the other hand, three-dimensional integrated circuits (3-D ICs) become more and more popular to satisfy the multi-function chip development. One of the best solutions of these needs is the ultra-fine pitch micro-bumps. The micro-bumps can...
The Joule heating effect at various stages under electromigration of flip-chip Sn3.5Ag solder joints was investigated under a current of 0.5 A at 100°C. During various stages of electromigration, voids may form and propagate and Joule heating effect may vary at different void sizes. To verify the void nucleation and propagation on Joule heating effect during electromigration process, the solder bump...
FinFET is the most promising double-gate transistor architecture to extend scaling over planar device. We present a high-performance and low-power FinFET module at 25 nm gate length. When normalized to the actual fin perimeter, N-FinFET and P-FinFET have 1200 and 915 ??A/??m drive current respectively at 100 nA/??m leakage under 1V. To our knowledge this is the best FinFET drive current at such scaled...
The electrical characterization of fine-pitch compliant Au bumps is investigated in this study. Compliant Au bumps of 20 microns pitch were fabricated on a glass substrate for chip-on-glass application. Kelvin probes are fabricated and employed to measure the bump resistance. The resistance ranges from 1.0 to 4.5 ohms, depending on process parameters. Current-carrying capability for these bumps is...
The Joule heating effect at various stages of electromigration of flip-chip Sn3.5Ag solder joints was investigated under a current of 0.5 Amp at 100??C. During various stages of electromigration, voids may form and propagate and Joule heating effect may vary at different void sizes. To verify the void nucleation and propagation on Joule heating effect during electromigration process, the solder bump...
We introduced a new low-profile UWB monopole antenna to achieve overhorizon operation from low VHF frequencies up to 2 GHz. The curvature profile of proposed Inverted-Hat Antenna is logarithmically related to the distance from the feed point, and thus results in a frequency-independent performance. The eleven-ellipse IHA is the most frequency-independent design. Other outer surface growth profiles...
The simulation results show that larger contact opening may not benefit on relieving current crowding effect in the flip-chip solder joints. For the solder joints with a 10-mum thick Cu UBM, the diameter of the contact opening for the lowest current crowding effect is 60 mum. It means that using larger or smaller diameter will increase the current density in the solder bumps. In addition, the optima...
The authors demonstrate a Ni/Cu bilayer structure for the under-bump-metallization (UBM) in Sn-Ag flip chip solder joints to enhance the electronmigration lifetime. The Ni layer provides two main contributions for the lifetime improvement. First, since Ni is a good diffusion barrier for Cu, it reduces the electromigration failure by UBM dissolution. Furthermore, the Ni layer limits the current crowding...
The electrical characterization of fine-pitch compliant Au bumps is investigated in this study. Compliant Au bumps of 20 microns pitch were fabricated on a glass substrate for chip-on-glass application. Kelvin probes are fabricated and employed to measure the bump resistance. The resistance ranges from 1.0 to 4.5 ohms, depending on process parameters. Current-carrying capability for these bumps is...
This study investigates electromigration study of eutectic SnPb flip-chip solder joints on ceramic substrates. The under bump metallization (UBM) structure consists of 5-mum Cu / 3-mum Ni under bump metallization (UBM). Under the current stressing by 0.9 A at 150degC, we did not find void formation but a large amount of intermetallic compound (IMC) of Cu6(Sn,Ni)5 were formed when the bump resistance...
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